def softwraphtml(value, max_line_length=20):
    import re
    whitespace_re = re.compile('\s')
    new_value = []
    unbroken_chars = 0
    in_tag = False
    in_xhtml_entity = False
    for idx, char in enumerate(value):
        if char == '<':
            in_tag = True
        elif char == '>':
            in_tag = False
            unbroken_chars = 0
        elif char == '&' and not in_tag:
            in_xhtml_entity = True
        elif char == ';' and in_xhtml_entity:
            in_xhtml_entity = False            
        elif whitespace_re.match(char):
            unbroken_chars = 0
        
        new_value.append(char)
        if not in_xhtml_entity:
            if unbroken_chars >= max_line_length-1 and not in_tag:
                new_value.append("<wbr/>")
                unbroken_chars = 0
            else:
                unbroken_chars += 1
    return ''.join(new_value)